The epizootic process of animal mycobacteriosis in countries around the world

Animal rabies is a viral disease that poses a significant threat to domestic and wild animal populations, with devastating consequences for animal health and human life. Understanding and assessing the risk factors associated with the transmission and persistence of the rabies virus in wild and domestic animal populations is crucial for developing effective strategies to control and mitigate cases. Studies of the spatial and temporal distribution of rabies cases in the Nizhny Novgorod region during 2012-2022 provided epidemiological evidence of the circulation of infection between animals in the presence of vaccination. Among the wild animals in the area, red foxes play a major role in the spread of rabies, accounting for 96.4% of all wild animal cases. We used spatiotemporal cluster analysis and a negative binomial regression algorithm to study the relationships between animal rabies burden by municipality and a series of environmental and sociodemographic factors. The spatiotemporal cluster analysis suggests the concentration of wild animal rabies cases in the areas of high fox population density and insufficient vaccination rates. The regression models showed satisfactory performance in explaining the observed distribution of rabies in different animals (R 2 = 0.71, 0.76, and 0.79 in the models for wild, domestic and all animals respectively), with rabies vaccination coverage and fox population density being among the main risk factors. We believe that this study can provide valuable information for a better understanding of the geographical and temporal patterns of rabies distribution in different animal species, and will provide a basis for the development of density-dependent planning of vaccination campaigns.

Zoonotic diseases impact both wild and domestic animal populations and can be transmitted to humans through close contact with animal species. Reservoir species acting as vectors are major traffickers of disease. Rodents contribute to the transmission of Coxiella burnetii although little is known about its prevalence in wild animal populations. DNA was extracted from genital swabs collected from woodland jumping mice, deer mice, Southern red-backed voles, Eastern chipmunks, North American red squirrels, as well as Southern and Northern flying squirrels collected from Algonquin Park, Canada. The presence of C. burnetii was determined through real-time PCR. All species sampled had some prevalence of infection, except Eastern chipmunks, indicating wild rodents in Algonquin Park are reservoirs for C. burnetii. Emerging zoonotic diseases are linked to increasing globalization. Contact amongst individuals increases as crowding, habitat loss and fragmentation increase within wild spaces. Parks often act as a last refuge for wildlife but may also be an important transmission zone of wildlife disease to humans. Investigations that attempt to discover wild reservoir species of zoonotic disease are critically important to understanding the risk of pathogen exchange between wild and human populations.

Infectious diseases can be a major threat to wildlife populations, especially in human-modified habitats, but infection rates in populations of wild animals are often poorly studied. Trichomonas, Salmonella, and Listeria are all pathogens known to infect birds, but their infection rates in wild bird populations are not well documented. This study documents infection rates of the three pathogens in wild bird populations inhabiting a suburban to rural gradient in Southeast Texas. Various species of wild birds were sampled at five sites in Southeastern Texas representing rural (<1 house per ha), exurban (approximately 1 house per ha), and suburban (approximately 10 houses per ha) habitat types. Birds were captured in mist nets and samples were taken from the oral cavity, crop, and vent to detect the presence of pathogens. Samples were screened for Trichomonas by examining wet mounts under a light microscope, whereas samples were screened for Salmonella and Listeria by examining colonies grown on agar plates. Pathogens detected during the initial screening were further confirmed by PCR and DNA sequencing. Infection rates for Trichomonas, Salmonella, and Listeria were 9%, 17%, and 5%, respectively. The distributions of infection rates across habitats (i.e., rural, exurban, rural) did not differ significantly from the expected null distributions for any of the three pathogens; however, the data suggested some interesting patterns that should be confirmed with a larger dataset. Infection rates for Trichomonas and Salmonella were highest at the suburban sites, whereas the infection rate for Listeria was highest at the rural site. Feeder birds were more likely to be infected by all three pathogens than non-feeder birds. Small sample sizes prevent definitive conclusions regarding variation in infection rates along the suburban to rural gradient, but the results suggest that pathogens followed the predicted patterns. For many of the bird species sampled, this study presents the first report of infection rates by these three pathogens in wild populations.

The prevalence of antibiotic-resistant bacteria in wild animal and bird populations is largely unknown, with little consistency among the few published reports. We therefore examined intestinal bacteria from magpies (Pica pica) and rabbits (Oryctolagus cuniculus) collected in rural west Wales. Escherichia coli isolates resistant to multiple antibiotics were grown from eight of 20 magpies trapped in spring, 1999 and one of 17 in spring, 2000; the most prevalent resistance trait among these isolates was to tetracycline, but resistances to ampicillin, chloramphenicol, kanamycin, sulphonamide, tetracycline and trimethoprim were also found. Tetracycline-resistant Enterococcus spp. were found in one of 20 magpies in 1999 and three of 17 in 2000. Only one resistant E. coli isolate was detected among gut bacteria from 13 rabbits, and this strain was resistant only to tetracycline. Differences in the prevalence of resistance between bacteria from rabbits and magpies may reflect differences in diet: rabbits graze field edges, whereas magpies are omnivorous and opportunistic. The resistance genes found in E. coli isolates from magpies mostly corresponded to those common among human isolates, but those conferring tetracycline resistance were unique.

Simple SummaryMycobacteriosis is a collective term for diseases caused by nontuberculous mycobacteria. Wild animals are a frequent source of mycobacteria infection in farm animals and humans; therefore, it is important to monitor the presence of these pathogens in free-living mammals. We isolated bacterium belonging to Mycobacterium kansasii complex from a submandibular lymph node obtained from a wild boar. This mycobacterium is a common cause of severe human lung diseases and is rarely responsible for animal diseases; therefore, its presence in the wild animal population is of great concern. The animal was apparently healthy, and we did not find any internal organ lesions despite the abundant growth of tissue-isolated bacteria on media. Thanks to our research, the specificity of wild boar mycobacteriosis caused by MKC will be better known.The most numerous group of bacteria in the genus Mycobacterium is the nontuberculous mycobacteria. Currently, over 200 species of bacteria have been classified as belonging to this group, of which approximately 30 are pathogenic to humans and animals. Mycobacterium kansasii complex numbers among these pathogenic species. The submandibular lymph nodes of a wild boar shot by a hunter were examined in order to confirm or exclude infection with bacteria of the genus Mycobacterium. In culture, a bacterial isolate was obtained after 12 days of incubation on Petragnani and Stonebrink media. A multiplex PCR clearly indicated that the isolate was a nontuberculous mycobacterium. The results of species identification attempts via both molecular biology methods and mass spectrometry confirmed that the isolated strain belonged to MKC. The described case of a wild boar infection with MKC is the first documented case in Poland and only the second in Europe, and in confirming the presence of this pathogen among free-living animals, this report implies that MKC is of great concern. Our research elucidates some specifics of wild boar mycobacteriosis and may be used to instill awareness in the public of the dangers of dressing hunt prey or consuming its meat in ignorance of safe procedures, which can contribute to the transmission of the pathogen to humans.

Astroviruses (AstVs) are small RNA viruses characterized by a high mutation rate, the ability to recombine, and interspecies transmission, which allows them to infect a multitude of hosts including humans, companion animals, and farmed animals as well as wildlife. AstVs are stable in the environment, and their transmission is usually through the fecal-oral route or via contaminated water and food. Although direct zoonotic transmission was not confirmed, interspecies transmission events have occurred or have been indicated to occur in the past between wild and domestic animals and humans. They cause large economic losses, mainly in the poultry sector, due to gastroenteritis and mortality. In young children, they are the second most common cause of diarrhea. This study involved 166 intestine samples and pools of spleen, lymph node, and kidney samples collected from 352 wild animals, 52 pigs, and 31 companion animals. Astroviruses were detected in the intestine samples and were separately detected in pools of tissue samples prepared for individual animals using a heminested RT-PCR protocol. Amplicons were subjected to Sanger sequencing, and a phylogenetic analysis of 320 nt RNA-dependent RNA polymerase (RdRp) fragments referring to known nt sequences of astroviruses was performed. Astroviral RNA was detected in the intestine samples and/or tissue pools of red foxes (nine positive intestines and six positive tissue pools), rats (two positive intestines and three positive tissue pools), a cat (one AstV detected in an intestine sample), pigs (eight positive tissue pools), and wild boars (two positive pools of spleens, kidneys, and lymph nodes). No astroviral RNA was detected in wild mustelids, dogs, or other small wild animals including rodents. A phylogenetic analysis revealed that the astroviruses detected during this study were mostly host-specific, such as porcine, canine, and rat astroviruses that were highly homologous to the sequences of reference strains. In one of two wild boars, an AstV distinct to porcine species was found with the highest nt identity to Avastroviruses, i.e., turkey astroviruses, which suggests potential cross-species transmission of the virus, as previously described. Here, we present the first detection of astroviruses in the population of wild animals, companion animals, and pigs in Poland, confirming that astroviruses are frequent pathogens circulating in animals in the field. Our study also suggests potential cross-species transmission of Avaastrovirus to wild boars; however, further molecular characterization is needed.

The global outbreak of highly pathogenic avian influenza (HPAI) H5N1 Eurasian lineage goose/Guangdong clade 2.3.4.4b virus that was detected in North America in 2021 is the largest in history and has significantly impacted wild bird populations and domestic poultry across the continent. Synanthropic birds may play an important role in transmitting the virus laterally to other wild bird species and domestic poultry. Understanding the dynamics of HPAI in atypical, or nonreservoir, wild bird hosts may help inform management decisions and potential risk factors to both wild and domestic bird populations. Following the confirmation of infections of HPAI H5N1 in domestic poultry at two commercial premises in Indiana, United States, we sampled and tested 266 Columbiformes and Passeriformes birds and found no detections of the virus at either location. We further queried laboratories within the National Animal Health Laboratory Network for avian influenza (AI) virus diagnostic test results for wild birds submitted from morbidity/mortality events, for a total of 9,368 birds tested across eight orders and 1,543 avian influenza virus detections between February 2022 and March 2023. Query results were assessed for viral prevalence by taxonomic group and suggested that the virus most often was observed in predatory and scavenging birds. The highest prevalence was observed in raptors (0.2514), with prevalence rates in exclusively scavenging Cathartidae reaching up to 0.5333. There is evidence that the consumption of infected tissues is a key pathway for transmission of AI viruses in predatory and scavenging birds. Although detections were found in nonpredatory synanthropic birds, including orders Columbiformes and Passeriformes, the risk of transmission from and between these groups appears comparatively low. Understanding the dynamics of AI viruses in synanthropic bird orders during the global HPAI H5N1 outbreak in wild bird populations can provide pertinent information on viral transmission, disease ecology, and risk to humans and agriculture.

We conducted a systematic review of the scientific literature from 1966 to 2005 to determine whether animals could provide early warning of a bioterrorism attack, serve as markers for ongoing exposure risk, and amplify or propagate a bioterrorism outbreak. We found evidence that, for certain bioterrorism agents, pets, wildlife, or livestock could provide early warning and that for other agents, humans would likely manifest symptoms before illness could be detected in animals. After an acute attack, active surveillance of wild or domestic animal populations could help identify many ongoing exposure risks. If certain bioterrorism agents found their way into animal populations, they could spread widely through animal-to-animal transmission and prove difficult to control. The public health infrastructure must look beyond passive surveillance of acute animal disease events to build capacity for active surveillance and intervention efforts to detect and control ongoing outbreaks of disease in domestic and wild animal populations.

Prior to the emergence of the A/goose/Guangdong/1/1996 (Gs/GD) H5N1 influenza A virus, the long‐held and well‐supported paradigm was that highly pathogenic avian influenza (HPAI) outbreaks were restricted to poultry, the result of cross‐species transmission of precursor viruses from wild aquatic birds that subsequently gained pathogenicity in domestic birds. Therefore, management agencies typically adopted a prevention, control, and eradication strategy that included strict biosecurity for domestic bird production, isolation of infected and exposed flocks, and prompt depopulation. In most cases, this strategy has proved sufficient for eradicating HPAI. Since 2002, this paradigm has been challenged with many detections of viral descendants of the Gs/GD lineage among wild birds, most of which have been associated with sporadic mortality events. Since the emergence and evolution of the genetically distinct clade 2.3.4.4 Gs/GD lineage HPAI viruses in approximately 2010, there have been further increases in the occurrence of HPAI in wild birds and geographic spread through migratory bird movement. A prominent example is the introduction of clade 2.3.4.4 Gs/GD HPAI viruses from East Asia to North America via migratory birds in autumn 2014 that ultimately led to the largest outbreak of HPAI in the history of the United States. Given the apparent maintenance of Gs/GD lineage HPAI viruses in a global avian reservoir; bidirectional virus exchange between wild and domestic birds facilitating the continued adaptation of Gs/GD HPAI viruses in wild bird hosts; the current frequency of HPAI outbreaks in wild birds globally, and particularly in Eurasia where Gs/GD HPAI viruses may now be enzootic; and ongoing dispersal of AI viruses from East Asia to North America via migratory birds, HPAI now represents an emerging disease threat to North American wildlife. This recent paradigm shift implies that management of HPAI in domestic birds alone may no longer be sufficient to eradicate HPAI viruses from a given country or region. Rather, agencies managing wild birds and their habitats may consider the development or adoption of mitigation strategies to minimize introductions to poultry, to reduce negative impacts on wild bird populations, and to diminish adverse effects to stakeholders using wildlife resources. The main objective of this review is, therefore, to provide information that will assist wildlife managers in developing mitigation strategies or approaches for dealing with outbreaks of Gs/GD HPAI in wild birds in the form of preparedness, surveillance, research, communications, and targeted management actions. Resultant outbreak response plans and actions may represent meaningful steps of wildlife managers toward the use of collaborative and multi‐jurisdictional One Health approaches when it comes to the detection, investigation, and mitigation of emerging viruses at the human‐domestic animal‐wildlife interface.

The 2020–2021 avian influenza epidemic with a total of 3,777 reported highly pathogenic avian influenza (HPAI) detections and approximately 22,900,000 affected poultry birds in 31 European Countries appears to be one of the largest HPAI epidemics that has ever occurred in Europe. Between 15 May and 15 September 2021, 162 HPAI virus detections were reported in 17 EU/EEA countries and the UK in poultry (51), in wild (91) and captive birds (20). The detections in poultry were mainly reported by Kosovo (20), Poland (17) and Albania (6). HPAI virus was detected during the summer months in resident wild bird populations mainly in northern Europe. The data presented in this report indicates that HPAI virus is still circulating in domestic and wild bird populations in some European countries and that the epidemic is not over yet. Based on these observations, it appears that the persistence of HPAI A(H5) in Europe continues to pose a risk of further virus incursions in domestic bird populations. Furthermore, during summer, HPAI viruses were detected in poultry and several wild bird species in areas in Russia that are linked to key migration areas of wild waterbirds; this is of concern due to the possible introduction and spread of novel virus strains via wild birds migrating to the EU countries during the autumn from the eastern breeding to the overwintering sites. Nineteen different virus genotypes have been identified so far in Europe and Central Asia since July 2020, confirming a high propensity for this virus to undergo reassortment events. Since the last report, 15 human infections due to A(H5N6) HPAI and five human cases due to A(H9N2) low pathogenic avian influenza (LPAI) virus have been reported from China. Some of these cases were caused by a virus with an HA gene closely related to the A(H5) viruses circulating in Europe. The viruses characterised to date retain a preference for avian‐type receptors; however, the reports of transmission events of A(H5) viruses to mammals and humans in Russia, as well as the recent A(H5N6) human cases in China may indicate a continuous risk of these viruses adapting to mammals. The risk of infection for the general population in the EU/EEA is assessed as very low, and for occupationally exposed people low, with large uncertainty due to the high diversity of circulating viruses in the bird populations.

Free‐range poultry farms have a high risk of introduction of avian influenza viruses (AIV), and it is presumed that wild (water) birds are the source of introduction. There is very scarce quantitative data on wild fauna visiting free‐range poultry farms. We quantified visits of wild fauna to a free‐range area of a layer farm, situated in an AIV hot‐spot area, assessed by video‐camera monitoring. A total of 5,016 hr (209 days) of video recordings, covering all 12 months of a year, were analysed. A total of 16 families of wild birds and five families of mammals visited the free‐range area of the layer farm. Wild birds, except for the dabbling ducks, visited the free‐range area almost exclusively in the period between sunrise and the moment the chickens entered the free‐range area. Known carriers of AIV visited the outdoor facility regularly: species of gulls almost daily in the period January–August; dabbling ducks only in the night in the period November–May, with a distinct peak in the period December–February. Only a small fraction of visits of wild fauna had overlap with the presence of chickens at the same time in the free‐range area. No direct contact between chickens and wild birds was observed. It is hypothesized that AIV transmission to poultry on free‐range poultry farms will predominantly take place via indirect contact: taking up AIV by chickens via wild‐bird‐faeces‐contaminated water or soil in the free‐range area. The free‐range poultry farmer has several possibilities to potentially lower the attractiveness of the free‐range area for wild (bird) fauna: daily inspection of the free‐range area and removal of carcasses and eggs; prevention of forming of water pools in the free‐range facility. Furthermore, there are ways to scare‐off wild birds, for example use of laser equipment or trained dogs.

Migratory waterfowl and shorebirds are known to be important reservoirs for influenza A viruses (IAV) and they have been repeatedly implicated as causing avian influenza virus (AIV) outbreaks in domestic poultry flocks worldwide. In recent years, wild birds have been implicated in spreading zoonotic H5 influenza viruses to many countries, which has generated high levels of public health concern. Trinidad and Tobago (T&T) is positioned along the wintering route of migratory birds from the Americas; every year, many species of wild birds stopover on the islands of T&T, potentially carrying AIVs and exposing local populations of wild and domestic birds, including commercial poultry, to infection. The aim of this study was to trap, sample, and test as many wild bird species as possible to see whether they were actively infected or previously exposed to AIV. A total of 38 wild birds were trapped, sampled, and tested for IAV RNA, antibodies specific for influenza A nucleoprotein (NP) and antibodies that were specific for H5 and H7 subtypes. Five of the samples tested antibody positive for IAV, while three of these samples had positive titres (≥16) for the H5 subtype, indicating that they were likely to have been previously infected with an H5 IAV subtype. One of the samples tested positive for IAV (M gene) RNA. These results highlight the potential threat that is posed by wild birds to backyard and commercial poultry in T&T and emphasise the importance of maintaining high levels of biosecurity on poultry farms, ensuring that domestic and wild birds are not in direct or indirect contact. The results also underline the need to carry out routine surveillance for AIV in domestic and wild birds in T&T and the wider Caribbean region.

Zooanthroponotic pathogens, which are transmitted from humans to nonhuman animals, are an understudied aspect of global health, despite their potential to cause significant disease burden in wild and domestic animal populations and affect global economies. Some key human‐borne pathogens that have been shown to infect animals and cause morbidity and mortality include measles virus (paramyxoviruses), influenza A virus (orthomyxoviruses), herpes simplex 1 virus (herpesviruses), protozoal and helminthic parasites, and bacteria such as methicillin‐resistant Staphylococcus aureus and Mycobacterium tuberculosis. However, zooanthroponotic pathogens are most commonly reported in captive animals or domestic livestock with close human contact; there, the potential for economic loss and human reinfection is most apparent. There is also the potential for infection in wild animal populations, which may threaten endangered species and decrease biodiversity. The emergence and reemergence of human‐borne pathogens in wildlife may also have negative consequences for human health if these pathogens cycle back into humans. Many of the anthropogenic drivers of zoonotic disease emergence also facilitate zooanthroponotic transmission. Increasing research to better understand the occurrence of and the potential for bidirectional pathogen transmission between humans and animals is essential for improving global health. Mt Sinai J Med 76:448–455, 2009. © 2009 Mount Sinai School of Medicine

Recent outbreaks of highly pathogenic avian influenza virus (AIV) in birds, humans and other mammalian species calls for a better understanding of virus dynamics in wild bird species and populations that act as maintenance hosts. Host ecology influences the transmission of pathogens and can be used to explore and infer pathogen dynamics. Most of the ecological processes proposed to explain AIV transmission in wild birds have been derived from studies conducted in the temperate and boreal regions of the northern hemisphere. We evaluate the role of two key drivers of AIV dynamics in a waterfowl community in Zimbabwe (southern Africa): (1) the recruitment of young birds and (2) the seasonal aggregation of birds. We analyse the seasonal variation of AIV prevalence in waterfowl and overlay these data with the phenology of reproduction and the seasonal variation in the local abundance of these species. We find that the breeding period of southern Afrotropical waterfowl species is more extended and somewhat less synchronized among species in the community than is the case in temperate and boreal waterfowl communities. Young birds are recorded at most times of the year, and these immunologically naïve individuals can therefore act as new hosts for AIV throughout the year within the wild bird population. Although host aggregation peaks in the cold‐dry to hot‐dry season, birds still aggregate throughout the year and this potentially spreads the opportunities for first infection of juveniles and other naïve birds temporally. We did not find a relationship between season, AIV prevalence in waterfowl, the influx of juveniles or the gradual aggregation of birds during the dry season. Therefore, the main drivers of AIV dynamics (juvenile influx and host abundance/aggregation), although present in Afrotropical regions, could not explain the AIV seasonal patterns in our study in contrast to results reported from temperate and boreal regions. These differences imply variation in the risk of AIV circulation in waterfowl and in the risk of spread to poultry, other animals or humans.

ObjectiveThe aim of our study was to identify possible natural reservoirs of Salmonella Enteritidis among wild birds.IntroductionSalmonella Enteritidis is dangerous for human due the reason of toxicoinfaction. These pathogen demonstrate high virulence for small children and people with chronic pathologies and can causes people die. The main source of infection to humans is birds (poultry and wild).Wild birds represent the natural reservoir of same bacterial pathogens. It is known that Salmonella can occupy an intestinal tract of birds. This colonization in general is constant, sometimes proceeds with an alternating fever, and usually, without clinical signs. Infected birds can transmit pathogens to other isolates in close contact. This usually occurs on the nesting during seasonal migrations. In the southern region of Ukraine are several points of intersection of migration routes of wild birds on the way from Europe to Africa and Asia (National Park “Askania Nova”and others).MethodsThe study was conducted in populations of wild birds in National Park “Askania Nova” and peninsula “Arabat arrow” (the Azov Sea coast). From bird selected samples of blood serum and egg yolks for research in serum plate agglutination test (SPA) and litter samples for bacteriological research.ResultsThe serological monitoring in populations of wild waterfowl in National Park “Askania Nova” (Ichthyaetus relictus, Sterna nilotica, Sterna herundo, Casarca ferruginea) has shown the presence of seropozitive individuals in adult birds (average 18%) and egg yolks (avarrage 12%). The bacteriological investigations confirmed circulation of Salmonella in this group of birds. 32.3% of all bacterial pathogens was Salmonella and more then half of them was the reprezentatives of serovar Salmonella Enteritidis.Similar studies were conducted on territory of peninsula “Arabat arrow” (the Azov Sea coast). The serological monitoring among of wild waterfowl (Ardea cinerea, Sterna caspia, Phalacrocorax carbo, Podiceps cristatus, Anas platyrhynchos, Cygnus olar) revealed the presence of antibodies in blood serum (avarrage 17%) and egg yolks (avarrage 10%). From litter samples was isolated a great deal of Enterobacteria (Escherichia coli. Salmonella, Citrobacter, Enterobacter), havever 34.8% of them were Salmonella and near half of Salmonella (53.2%) was reprezentatives of serovar Salmonella Enteritidis.ConclusionsIt is proved that M. gallisepticum can persist among decorative waterfowl for her welfare with Galliformes, while waterfowl is a reservoir of the pathogen. Also natural reservoirs of Mycoplasma can be wild waterfowl (Casarca ferruginea). Such groups (populations) of birds may serve as a source of infection for commercial herds.This shows that wild waterfowl are the natural reservoir for these dangerous pathogens like Salmonella Enteritidis. The carriers may account for 17–18% of all individuals in the population. In nesting different species of wild birds may be infected by Salmonella Enteritidis. In the process of migrating wild birds can carry Salmonella Enteritidis over long distances and is a threat to commercial poultry flocks and humans.